DE102009014042A1 - Refrigerant cycle system - Google Patents

Abstract

In a refrigerant cycle system, a compression mechanism (11b) of an electric compressor (11) sucks and compresses refrigerant, and an electric motor (11a) that drives the compression mechanism (11b) is cooled by the refrigerant. A variable throttle mechanism (12, 16) decompresses the refrigerant discharged from the electric compressor (11). An engine temperature detecting means (20) detects a temperature of the electric motor (11a). A motor protection determining means (20) determines whether the temperature of the electric motor (11a) detected by the motor temperature detecting means (20) is equal to or higher than a judgment scale value. A motor protection controller (20) controls the variable throttle mechanism (12, 16) so that an opening degree of the variable throttle mechanism (12, 16) does not decrease when the motor protection determining means (20) determines that the temperature of the electric motor (11a) is equal to or higher than is the rating scale value.

Description

The The present invention relates to a refrigerant cycle system with an electric compressor.

Conventionally, in an electric compressor in which a compression mechanism and an electric motor for driving the compression mechanism are integrated, temperature protection control is performed, such as in FIG JP 2006-291878 A and JP 2005-248730 A disclosed. In order to avoid an excessive temperature rise of the electric motor, the temperature protection control is performed when the temperature of a power converter, the electric motor, etc. rises excessively due to a high load state of the electric compressor.

In JP 2006-291878 A the temperature of the electric motor is evaluated on the basis of the engine speed of the electric compressor, the input current of the power converter, etc. The excessive temperature increase of the electric motor is avoided by the electric compressor is turned off when the evaluated temperature of the electric motor exceeds a predetermined value. In JP 2005-248730 A For example, the electric compressor has a structure in which refrigerant sucked into the electric compressor cools a power converter including a driving circuit for the electric motor. In the electric compressor, the motor speed of the electric motor is increased or the electric compressor is turned off to suppress the temperature rise of the power converter, which occurs when the speed of the electric converter is small, although the torque that should be generated by the electric motor, high is.

In JP-2006-291878 A the electric compressor is turned off to prevent the temperature rise of the electric motor. However, when a refrigerant cycle system having the electric compressor is applied to a vehicle air conditioning system, there is a problem that the air conditioning feeling, etc. in a passenger compartment becomes considerably worse.

The construction of in JP 2005-248730 A disclosed compressor is to protect a power conversion device from excessive temperature rise. However, when the temperature of the power converter increases, a current value input to the electric motor is also high. Therefore, the heat generation in the electric motor is large, and the electric motor is a high-temperature state. In this situation, a temperature protection control of the electric motor is performed by using the electric compressor as in JP 2006-291878 is turned off, and the same problem as in JP 2006-291878 A occurs.

The The present invention is made in view of the above-mentioned Problems made. Consequently, it is an object of the present invention Invention, a refrigerant cycle system available to provide the temperature protection control, an excessive temperature rise to avoid an electric motor of an electric compressor without turning off the electric compressor more than necessary.

Around to achieve the object of the present invention is a Refrigerant cycle system provided that an electrical Compressor, a variable throttle mechanism, an engine temperature detector, a motor protection determining device and a motor protection control has. The electric compressor comprises a compression mechanism, the refrigerant is sucked in and compressed, and an electric motor, which drives the compression mechanism and that on a suction side the compression mechanism of the refrigerant cooled becomes. The variable throttle mechanism decompresses that of the electric compressor expelled refrigerant. The engine temperature detecting means detects a temperature of the electric motor. The engine protection determining device determines whether the temperature detected by the engine temperature detecting means of the electric motor is equal to or higher than a judgment scale value is. The motor protection control controls the variable throttle mechanism, allowing an opening degree of the variable throttle mechanism does not decrease when the engine protection device determines that the temperature of the electric motor is equal or higher as the judgment scale value.

The Invention, together with its additional objects, Features and advantages best seen in the following description, the appended claims and the accompanying drawings understood, wherein:

1 is a schematic diagram showing the structure of a refrigerant cycle system according to a first embodiment of the present invention;

2 FIG. 12 is a block diagram showing an electric control portion of the refrigerant cycle system according to the first embodiment; FIG.

3 FIG. 10 is a flowchart showing a method of setting an opening degree of an electric expansion valve of the refrigerant cycle system according to the first embodiment; FIG.

4 FIG. 14 is a control line diagram showing an engine temperature related to a motor current and a motor rotational speed of an electric motor of an electric compressor of the refrigerant cycle system according to the first embodiment; FIG.

5 is a schematic diagram showing the structure of a refrigerant cycle system according to a second embodiment of the present invention;

6 FIG. 10 is a flowchart showing a main part of a method of setting the opening degree of an electric expansion valve of the refrigerant cycle system according to the second embodiment; FIG. and

7A . 7B Are control map diagrams showing an engine temperature related to a motor current and a motor rotational speed of an electric motor of an electric compressor of the refrigerant cycle system according to the second embodiment.

First Embodiment

A first embodiment of the present invention will be described below with reference to FIG 1 - 4 described. 1 FIG. 10 is a schematic diagram showing an overall structure of a refrigerant cycle system according to the first embodiment applied to a vehicle air conditioning system. As in 1 1, the vehicle air conditioning system according to the first embodiment has an interior air conditioning unit 1 Installed inside an instrument panel located at a foremost part of a passenger compartment of a vehicle to form a dashboard, etc.

The interior air conditioning unit 1 has a housing element 2 made of resin. The housing element 2 forms an outer shell of the interior air conditioning unit 1 and takes constituent devices of the indoor air conditioning unit 1 in it. This housing element 2 defines an air passage through which air is blown into the passenger compartment of the vehicle.

An indoor / outdoor air switching box 3 is in the most upstream portion of the air passage of the housing member 2 Installed. The indoor / outdoor air switching box 3 has an intake opening 3a and an outside air inlet opening 3b , An inside / outside air switching door 3c is rotatable in the inside / outside air switching box 3 Installed.

The indoor / outdoor air switching door 3c is driven by a servomotor (not shown) to switch between an inside air mode, an outside air mode, and an inside / outside air mode. In the inside air mode is through the inside air inlet 3a Indoor air (air inside the passenger compartment) introduced into the passenger compartment. In the outside air mode is through the outside air inlet 3b Outside air (air outside the passenger compartment) introduced into the passenger compartment. In the indoor / outdoor air mode, both indoor air and outdoor air are introduced into the passenger compartment.

An electric fan 4 is on a downstream side of the inside / outside air switching box 3 Installed. The electric fan 4 blows the air into the passenger compartment. The electric fan (second electric fan) 4 is an electrically driven blower in which a well-known multi-wing centrifugal fan (sirocco fan) from an electric motor 4a is driven. The speed of the electric motor 4a can be controlled by a control voltage from an air conditioning control described later 20 is issued.

An evaporator 5 is on a downstream side of the electric fan 4 Installed. The evaporator 5 is one of the constituent devices comprising a refrigerant cycle system 10 which will be described later. In addition, evaporates the evaporator 5 Low-pressure side refrigerant entering the evaporator 5 has flowed to absorb heat. The evaporator works 5 as a cooling heat exchanger, that of the electric fan 4 blown air cools.

A heater core 6 is on a downstream side of the evaporator 5 installed in an air flow direction. The heater core 6 is a heat exchanger for heating the air, which is the evaporator 5 using the heat of hot water, which is heated by an electric heater heats. The hot water heated by the electric heater, etc. is introduced into the heater core through an electric pump (not shown) 6 fed.

Bypass passages 7 are on the sides of the heater core 6 arranged. The air flows through the bypass passages 7 to the heater core 6 to get around. In addition, air mixing flaps are rotatable on the sides of the heater core 6 arranged. The air mixing valves 8th act as an air temperature adjuster. The air mixing valves 8th are driven by a servomotor (not shown) so that the rotational position (opening degree) of the air mix door 8th can be adjusted continuously.

By adjusting the opening degree of the air mixing flap 8th is the ratio between the amount of air that is the heater core 6 passes through, and the amount of air passing the bypass passages 7 goes through, set. In this way, the temperature of the air on a downstream side of the heater core 6 set. In this embodiment, the bypass passages are 7 on both sides of the heater core 6 arranged.

Consequently, the air mixing valves are also 8th on both sides of the heater core 6 arranged, and the two air mixers 8th are controlled in conjunction with each other.

A defroster blowing port (not shown), a face blowing port (not shown), and a foot blowing port (not shown) are at the most downstream part of the air passage of the housing member 2 arranged. Conditioned air is exhausted through the defroster blowing opening toward a front window glass (windshield) of the vehicle, through the face blowing opening toward an upper body of the passenger and through the foot blowing opening toward the feet of the passenger. Opening / closing flaps are rotatably disposed on upstream sides of these exhaust openings. The opening / closing flaps open or close by being driven by a common servomotor by means of a link mechanism (not shown).

Next, the refrigerant cycle system 10 described. The refrigerant cycle system 10 has in addition to the above-mentioned evaporator 5 an electric compressor 11 , an outside heat exchanger 13 , an electric expansion valve 16 , an accumulator 18 , Etc.

In the electric compressor 11 are an electric motor 11a and a compression mechanism 11b that of the electric motor 11a is driven, integrated. The electric motor 11a is located on a suction side of the electric compressor 11 and is caused by cold refrigerant entering the electric compressor 11 is sucked, cooled.

The electric motor 11a is a three-phase AC motor. The compression mechanism 11b For example, it is a well-known spiral compression mechanism. In addition, the speed of the electric motor 11a from a power converter unit 19 , which will be described later, variably controlled.

The outside heat exchanger 13 is with a discharge side of the electric compressor 11 connected. On the outside heat exchanger 13 exchanges the refrigerant coming from the electric compressor 11 is discharged and has a high temperature and high pressure, heat with the outside air (air outside the passenger compartment) off. Consequently, the outside heat exchanger acts 13 as a heat radiating heat exchanger. The outside air is supplied by an electrically driven cooling fan (first electric fan) 13a to the outside heat exchanger 13 blown. The cooling fan 13a is powered by an electric motor 13b driven. The speed of the electric motor 13b is controlled by the controlled voltage provided by the air conditioning control 20 which will be described later.

The electric expansion valve 16 That works as a variable throttle mechanism is with an outlet side of the outside heat exchanger 13 connected. The electric expansion valve 16 works as a pressure control valve. An opening degree of the pressure control valve is electrically controlled, so that the discharge refrigerant pressure Pd, which is the pressure of the refrigerant on the discharge side of the electric compressor 11 is to be a target high pressure at a normal operating time of the refrigerant circuit. The electric expansion valve 16 Also works as a control valve, which increases the temperature of the electric motor 11a of the electric compressor 11 stops when the temperature of the electric motor 11a is high.

In particular, the electrical expansion valve comprises 16 an electrical actuator mechanism 16a and a valve mechanism provided by the electrical actuator mechanism 16a is driven. A stepper motor, for example, serves as the electrical actuator mechanism 16a , An opening degree of the valve mechanism can be exactly corresponding to a working angle of the electric actuator mechanism 16a be set. The opening degree of the electric expansion valve 16 is from the air conditioning control 20 , which will be described later, controlled.

The above-mentioned evaporator 5 is with an outlet side of the electric expansion valve 16 connected. The accumulator 18 is with the outlet side of the evaporator 5 connected. The accumulator 18 is a gas / liquid separator, that of the evaporator 5 drained refrigerant into gaseous refrigerant (saturated gas-phase refrigerant) and liquid refrigerant (saturated liquid-phase refrigerant) and collects excess refrigerant in the refrigeration cycle. That in the accumulator 18 separated gaseous refrigerant becomes the suction side of the electric compressor 11 initiated.

An overview of an electric control unit according to the first embodiment will be described hereinafter. 2 is a blockdia gram showing the electrical control section. The air conditioning control 20 consists of a well-known microcomputer comprising a CPU, a ROM, a RAM, etc. and a peripheral circuit of the microcomputer. The air conditioning control 20 performs various calculations and operates operations of electrical devices such as the power converter unit based on a control program stored in the ROM 19 of the electric compressor 11 , the electric motor 13b the cooling fan 13a , the electrical actuator mechanism 16a of the electric expansion valve 16 and the electric motor 4a of the electric fan 4 to control.

The power converter unit 19 of the electric compressor 11 will be briefly described here below. The electric motor 11a of the electric compressor 11 , which is a three-phase three-phase motor, is rotationally driven by the three-phase electric power supplied from a power device 190 the power converter unit 19 is converted and output. The speed of the electric motor 11a is from a power converter control section 191 (adjustable speed control) precisely and variably controlled.

The power converter control section 191 includes a CPU 192 , a communication circuit 193 , etc. The power converter control section 191 communicates with the air conditioning control 20 and controls the speed of the electric motor 11a of the electric compressor 11 , so that the speed should be set to an optimum value.

The power converter control section 191 Captures motor current to the electric motor 11a is output, and the rotational speed of the electric motor 11a and gives the detection values to the air conditioner controller 20 out. The power source of the power converter unit 19 is a battery 21 which is mounted on the vehicle.

An input side of the air conditioning control 20 is with a discharge pressure sensor 31 , an outside refrigerant temperature sensor 32 , a post-evaporator air temperature sensor 33 etc. connected. The discharge pressure sensor 31 serves to detect the discharge refrigerant pressure Pd. The outside refrigerant temperature sensor 32 is for detecting the outside refrigerant temperature Tho, which is the temperature of the refrigerant on the outlet side of the outside heat exchanger 13 is. The reboiler air temperature sensor 33 is used to detect the blown air temperature Te, which is the temperature of the evaporator 5 blown air is.

The detection signals from sensors 34 which include an outside air temperature sensor, an inside air temperature sensor, a solar radiation sensor, etc., are also included in the air conditioning control 20 entered. These sensors 31 - 34 serve as different detection means in the first embodiment. In addition, near the dashboard (instrument panel) in the passenger compartment is an air conditioning control panel 40 arranged. Various air conditioning control signals are from controls of the A / C control panel 40 in the air conditioning control 20 entered.

In particular, the various air conditioning control signals included by the air conditioning control panel 40 an internal temperature setting signal, an air flow volume switching signal of the electric blower 4 , an air-blowing mode switching signal, an inside / outside air introduction mode switching signal of the inside / outside air switching box 3 , etc. The internal temperature setting signal is set by a temperature setting switch. The air volume switching signal is set by an airflow selector switch. The air-blowing mode switching signal is set by an air-blowing mode selection switch. The inside / outside air mode switching signal is set by an inside / outside air selection switch.

Next, the operation of the refrigerant cycle system according to the first embodiment having the above-described structure will be described hereinafter. First, a basic operation of the refrigerant cycle system will be described hereinafter 10 described. If the control (the air conditioner switch) of the air conditioner control panel 40 is switched and the compressor activating command signal is generated, the electric motor 11a through the power converter unit 19 powered by electrical energy, and the electric motor 11a turns. The driving force of the electric motor 11a gets to the compression mechanism 11b transferred, and the electric compressor 11 is driven.

The refrigerant is supplied by the electric compressor 11 compressed, and the refrigerant has a high temperature and a high pressure. The high-temperature, high-pressure refrigerant flows into the outside-side heat exchanger 13 , On the outside heat exchanger 13 The refrigerant exchanges heat with the outside air from the cooling fan 13a is blown to radiate heat to the outside air.

Then that will be from the outside heat exchanger 13 discharged refrigerant from the electric expansion valve 16 decompressed and placed in a gas-liquid two-phase state of low temperature and low pressure. The gas-liquid two-phase refrigerant having the low temperature and the low pressure flows into the evaporator 5 , At the evaporator 5 The refrigerant is vaporized by absorbing heat from the air coming from the electric fan 4 is blown. This will remove the from the electric fan 4 blown air from the evaporator 5 cooled down, and the cooled air can be blown into the passenger compartment.

Then, the low pressure refrigerant flowing to the evaporator flows 5 has gone through, into the accumulator 18 , At the accumulator 18 The low-pressure refrigerant is separated into the saturated liquid-phase refrigerant and the saturated gas-phase refrigerant. The saturated gas-phase refrigerant is discharged from an outlet of the accumulator 18 to the suction side of the electric compressor 11 initiated. Then the saturated gas-phase refrigerant enters the electric compressor 11 sucked in and is compressed again.

Next, here below is the basic control method used by the air conditioner controller 20 is performed according to the first embodiment is described. This control process starts when the air conditioner switch is turned on under the condition that a starter switch (not shown) of the vehicle is turned on.

First, a flag, a timer, etc. are initialized. Then, detection signals of the sensors become 31 - 34 and operating signals of the air conditioning control panel 40 read. Then control states of the actuators 4a . 13b . 16a . 19 etc. determined.

More specifically, a target blow-off temperature TAO at which the air should be blown into the passenger compartment is calculated based on the target air temperature Tsoll in the passenger compartment, the inside air temperature Tr, and the outside air temperature Tam. In addition, based on the target exhaust temperature TAO, a target rotation speed of the electric blower becomes 4 (one to the electric motor 4a applied voltage), a target speed of the cooling fan 13a the outside heat exchanger 13 (one to the cooling fan 13a applied voltage), a target opening degree of the air mix doors 8th (Control signals sent to the servo motor for the air mixing valves 8th output).

In addition, based on the target blow-off temperature TAO, a target evaporator blow-off temperature TEO is determined. The target blow-off temperature TEO is a target value for the cooling dimension of the evaporator 5 , Then, a refrigerant discharge capacity of the electric compressor becomes 11 (Control signal to the power converter unit 19 is output), so that the blow-out air temperature Te of the evaporator 5 should approach the target evaporator outlet temperature TEO.

In addition, based on the outside refrigerant temperature Tho (temperature of the refrigerant on the outlet side of the outside heat exchanger 13 ) determines a target high pressure Po. The target high pressure Po maximizes the efficiency of the refrigeration cycle (coefficient of performance). The opening degree of the electric expansion valve 16 (The control signal to the electrical actuator mechanism 16a is output) is determined, so that the discharge refrigerant pressure Pd of the electric compressor 11 the above-mentioned target high pressure Po should be.

Then be from the air conditioning control 20 Output signals to the actuators 4a . 11a . 13b . 16a , etc., issued to the control states of the actuators 4a . 13b . 16a . 19 etc. that have already been determined to realize.

In the electric compressor 11 in the first embodiment, the electric motor 11a from the cold refrigerant that enters the electric compressor 11 is sucked, cooled. When the motor current coming from the rectifier unit 19 to the electric motor 11a is output, is high and the speed of the electric motor 11a is small, becomes the electric motor 11a from the cold refrigerant that enters the electric compressor 11 is sucked, occasionally not sufficiently cooled down, and the electric motor 11a can be in a high temperature state.

In such a case, the electric compressor becomes 11 switched off in a conventional refrigerant cycle system. In the first embodiment, instead, the opening degree of the electric expansion valve 16 controlled to a temperature protection control to prevent a temperature rise of the electric motor 11a of the electric compressor 11 perform.

The temperature protection control for the electric motor 11a in the first embodiment will be described hereinafter with reference to 3 . 4 described. 3 FIG. 12 is a flowchart illustrating a method of setting the opening degree of the electric expansion valve. FIG 16 shows that from the air conditioning control 20 is carried out. 4 is a control characteristic diagram showing the temperature of the electric motor 11a shows that with the motor current and the speed of the electric motor 11a of the electric compressor 11 in the first embodiment.

The method for setting the opening degree of the electric expansion valve 16 , this in 3 is shown starts when the refrigerant circuit is turned on, that is, when the electric compressor 11 is turned on. First, the air conditioner controller reads 20 at step S100, the detection signals of the sensors, the various air conditioning operation signals received from the air conditioning control panel 40 to be sent, etc.

In particular, the air conditioner controller reads 20 the discharge refrigerant pressure Pd discharged from the discharge pressure sensor 31 is detected, the outside refrigerant temperature Tho (temperature of the refrigerant on the outlet side of the outside heat exchanger 13 ) received from the outside refrigerant temperature sensor 32 is detected, the value of the motor current supplied by the power converter unit 19 to the electric motor 11a is output, the rotational speed of the electric motor 11a , Etc.

Next, the air conditioning control calculates 20 a control amount of the opening degree of the electric expansion valve 16 such that the discharge refrigerant pressure Pd supplied from the discharge pressure sensor 31 is detected to be the target high pressure Po based on the outside refrigerant temperature Tho (temperature of the refrigerant on the outlet side of the outside heat exchanger 13 ), which is determined by the outside-side refrigerant temperature sensor 32 is detected. In the first embodiment, the opening degree of the electric expansion valve becomes 16 increases when the control amount of the opening degree is greater than zero, and the opening degree of the electric expansion valve 16 is reduced when the control amount of the opening degree is smaller than zero.

In addition, the in 4 shown control characteristic in the first embodiment in advance in the ROM, etc. of the air conditioning control 20 saved. In this control curve, the temperature of the electric motor depends 11a with the speed and the motor current of the electric motor 11a put together by the power converter unit 19 be recorded. The temperature of the electric motor 11a is inversely proportional to a flow rate of the refrigerant, namely the rotational speed of the electric motor 11a , The temperature of the electric motor 11a is proportional to heat generation in the electric motor 11a , namely a square of the value of the motor current. For example, the temperature of the electric motor 11a low when the speed of the electric motor 11a is high and the motor current is small. The temperature of the electric motor 11a gets high when the speed of the electric motor 11a is small and the motor current is high.

In the first embodiment, the temperature of the electric motor 11a calculated and recorded based on the control curve. Alternatively, the temperature of the electric motor 11a by inputting the rotational speed of the electric motor 11a and the value of the motor current into a calculation equation, etc.

In the control characteristic are judgment scale values for the temperature of the electric motor 11a specified to determine if the temperature rise of the electric motor 11a should be avoided or not. Specifically, in the control characteristic of the first embodiment, first to third judgment scale values are the judgment scale values for the temperature of the electric motor 11a specified, and a limit for the temperature of the electric motor 11a is also specified.

The relationship between the judgment scale values and the limit value is: (first judgment scale value) <(second judgment scale value) <(third judgment scale value) <(limit value). The first to third judgment scale values and the limit value of the temperature of the electric motor 11a are specified so that the speed of the electric motor 11a should rise when the value of the motor current increases when the temperature of the electric motor 11a is kept at one of the first to third judgment scale values or the threshold value. A first judgment scale line showing the speed and motor current of the electric motor 11a indicative of the first judgment scale value, a second judgment scale line indicating the rotational speed and the motor current of the electric motor 11a indicative of the second judgment scale value, a third judgment scale line indicating the rotational speed and the motor current of the electric motor 11a indicating the third judgment scale value, and a boundary line representing the rotational speed and the motor current of the electric motor 11a indicating that they correspond to the limit are parallel to each other.

The first to third judgment scale lines and the limit line separate the temperature of the electric motor 11a of the electric compressor 11 in areas A-D and an area outside the limit. In particular, the temperature of the electric motor 11a in the area A on the basis of the control characteristic, which is the temperature of the electric motor 11a with the speed and the motor current of the electric motor 11a lower than the first rating scale value. In area B is the temperature of the electric motor 11a is equal to or higher than the first judgment scale value and lower than the second judgment benchmark value. In the area C is the temperature of the electric motor 11a is equal to or higher than the second judgment scale value and lower than the third judgment benchmark value. In the area D is the temperature of the electric motor 11a equal to or higher than the third judgment scale value and lower as the limit. In the area outside the limit, which the diagonally hatched area in 4 is, is the temperature of the electric motor 11a equal to or higher than the limit.

The regions A-D and the region outside the limit are indices representing the temperature conditions of the electric motor 11a of the electric compressor 11 Show. The area A shows a normal state of the temperature of the electric motor 11a at. The region outside the limit value shows an abnormal temperature state of the temperature of the electric motor 11a in which the temperature of the electric motor 11a is excessively high (for example 120 ° C) and an insulation fault of a winding in the electric motor 11a can occur. The ranges B-D are set between the range A and the range outside the threshold and indicate a condition in which the temperature protection control for the electric motor 11a necessary is.

In step S300 in FIG 3 calculates and records the air conditioning control 20 the current temperature of the electric motor 11a according to the speed and the motor current of the electric motor 11a based on the control characteristic. Then the air conditioner controller calculates 20 the current temperature of the electric motor 11a in the range of the above-mentioned control characteristic. Then the air conditioning control determines 20 at step S400, whether or not the temperature of the electric motor determined at step S300 is A or not.

If it is determined at step S400 that the temperature of the electric motor 11a in the area A, sets the air conditioning control 20 the control amount calculated at step S200 as the control amount of the opening degree of the electric expansion valve 16 fixed (step S500). That is, the discharge refrigerant pressure Pd of the electric compressor 11 can be maintained at the target high pressure Po, which realizes the optimal control of the refrigeration cycle.

If it is not determined at step S400 that the temperature of the electric motor 11a in the area A, the air conditioning control determines 20 in step S410, whether the control amount of the opening degree of the electric expansion valve 16 calculated at step S200 is greater than zero or not. When it is determined at step S410 that the control amount is less than zero, the opening degree of the electric expansion valve becomes 16 controlled so that it decreases. Consequently, the air conditioner control sets 20 the control amount at step S420 to zero to change the control amount to a value that the opening degree of the electric expansion valve 16 will not change. When it is determined at step S410 that the control amount is greater than or equal to zero, the air conditioner controller changes 20 the control amount is not, and the process goes to step S430.

Next determines the air conditioning control 20 at step S430, whether the temperature of the electric motor 11a in the area B or not. When it is determined at step S430 that the temperature of the electric motor 11a in the area B, the process goes to step S500, and the air conditioner controller 20 sets the control amount equal to or greater than zero as the control amount of the opening degree of the electric expansion valve 16 firmly.

Consequently, if the temperature of the electric motor 11a is in the area B, at least the opening degree of the electric expansion valve becomes 16 controlled so that it does not decrease. That is, at least the increase of the discharge refrigerant pressure Pd of the electric compressor is inhibited, so that it is possible to increase the load of the electric compressor 11 and the temperature rise of the electric motor 11a to avoid.

If it is not determined at step S430 that the temperature of the electric motor 11a in the area B, the air conditioner determines 20 in step S440, whether the temperature of the electric motor is in the region C or not. If it is determined at step S440 that the temperature of the electric motor 11a in the area C, adds the air conditioning control 20 a first predetermined value Alpha to the control amount of the opening degree of the electric expansion valve 16 calculated at step S200, or adds the first predetermined value Alpha to the control amount set to zero at step S420.

Then, the procedure goes to step S500, and the air conditioner controller 20 sets the control amount to which the first predetermined value Alpha is added as the control amount of the opening degree of the expansion valve 16 firmly. Consequently, if the temperature of the electric motor 11a is in the range C, the opening degree of the electric expansion valve becomes 16 controlled so that it increases. That is, the discharge refrigerant pressure Pd of the electric compressor 11 is reduced so that it is possible to reduce the load of the electric compressor 11 to lower and increase the temperature of the electric motor 11a to avoid.

If it is not determined at step S440 that the temperature of the electric motor 11a in the area C determines the air conditioning control 20 at step S460, if the temperature of the electric motor 11a in the area D or not. When it is determined at step S460 that the temperature of the electric motor 11a in the area D, the Air conditioning control 20 at step S470, a second predetermined value Beta to the control amount of the opening degree of the electric expansion valve 16 calculated at step S200, or adds the second predetermined value Beta to the control amount set to zero at step S420.

Then, the procedure goes to step S500, and the air conditioner controller 20 sets the control amount to which the second predetermined value Beta is added as the control amount of the opening degree of the electric expansion valve 16 firmly. The second predetermined value Beta added at step S460 is a value greater than the first predetermined value Alpha added at step S450 ((first predetermined value Alpha) <(second predetermined value Beta)). Consequently, if the temperature of the electric motor 11a is in the range D, the opening degree of the electric expansion valve becomes 16 controlled so that it continues to increase as if the temperature of the electric motor 11a in the area C is.

That is, by gradually reducing the discharge refrigerant pressure Pd of the electric compressor 11 It will be possible to increase the temperature of the electric motor 11a to avoid putting the load of the electric compressor 11 is reduced, and a sudden change of the discharge refrigerant pressure Pd of the electric compressor 11 that deteriorates the air conditioning feeling, etc. in the passenger compartment.

If it is not determined at step S460 that the temperature of the electric motor 11a in the area D, the air conditioning control determines 20 at step S480 that the temperature of the electric motor 11a Anomalous is the anomaly in the ROM etc. of air conditioner control 20 ,

When the temperature of the electric motor 11a is in the range outside the limit, it is expected that the refrigerant cycle system 10 can collapse. Therefore, the operation of the electric compressor 11 switched off. The determination processes in steps S400, S430, S440, S460 correspond to protection determination means, and the processes in steps S420, S450, S470 correspond to a motor protection control means.

When the temperature of the electric motor 11a of the electric compressor 11 As described above, equal to or higher than the first judgment scale value, at least the opening degree of the electric expansion valve becomes 16 controlled so that it does not decrease. Consequently, it is possible to increase the discharge refrigerant pressure Pd of the electric compressor 11 to avoid. In this case, at least the increase of the load of the electric compressor 11 avoided, and it is possible to avoid the increase of the motor current, which is connected to the electric motor 11a is issued. Therefore, it is possible to use the temperature protection control for preventing the temperature rise of the electric motor 11a perform without the electric compressor 11 off.

In addition, the temperature of the electric motor 11a on the basis of the control characteristic, which is the temperature of the electric motor 11a with the speed and the motor current of the electric motor 11a linked, calculated and recorded. Consequently, it is possible to provide the temperature protection control for preventing the temperature rise of the electric motor 11a perform when the temperature of the electric motor 11a is equal to or higher than a judgment scale value.

Moreover, it is in detecting the temperature of the electric motor 11a on the basis of the control characteristic possible, the temperature protection control to avoid the temperature rise of the electric motor 11a perform without the electric motor 11a with a detection device exclusively for detecting the temperature of the electric motor 11a to provide. Consequently, it is possible to design the electric compressor 11 to simplify.

In addition, by specifying more than two judgment scale values (the first to third judgment scale values) as the judgment scale value in the control characteristic, it is possible to set the opening degree of the electric expansion valve 16 gradually cease. Therefore, it is possible to prevent the air conditioning feeling, etc. in the passenger compartment from being deteriorated. In the first embodiment, the first to third judgment scale values are specified as the judgment scale value. The present invention is not limited to this, and it is also possible to increase or decrease the number of the judgment scale value (s).

Second Embodiment

Next, hereinafter, with reference to FIG 5 - 7 A second embodiment of the present invention is described. Elements that are substantially equal to or equivalent to those in the first embodiment have the same reference numerals as in the first embodiment and will not be described again. 5 FIG. 10 is a schematic diagram showing an overall structure of a refrigerant cycle system according to the second embodiment applied to a vehicle air conditioning system. The refrigerant cycle system 10 According to the second embodiment, as a heat pump refrigeration constructed circuit, which can be switched between a cooling mode and a heating mode.

As in 5 In the second embodiment, a heater core is shown 6 in a housing element 2 an interior air conditioning unit 1 arranged. The heater core 6 is one of the constituent devices that the refrigerant cycle system 10 form. The heater core 6 works as a utility side heat exchanger, which is the air, which is an evaporator 5 has been heated using the high-temperature, high-pressure refrigerant as a heating source. The heater core 6 Also works as a heat radiating heat exchanger, which transfers the refrigerant by radiating heat to the air, which is the evaporator 5 has passed through, cools.

The refrigerant cycle system 10 according to the second embodiment has the evaporator 5 , the heater core 6 , an electric compressor 11 , a first electric expansion valve 12 , an outside heat exchanger 13 , an indoor heat exchanger 15 , a second electric expansion valve 16 , which corresponds to the electric expansion valve in the first embodiment, an accumulator 18 etc. In the following description, the heater core 6 as a use-side heat exchanger explained.

An inlet side of the above-mentioned use-side heat exchanger 6 is with a discharge side of the electric compressor 11 connected. The first electric expansion valve 12 acting as a variable throttle mechanism is with an outlet side of the utilization side heat exchanger 6 connected.

The first electric expansion valve 12 also works as a high pressure control valve. The degree of opening of the high pressure control valve is controlled by control signals provided by an air conditioning control 20 are output, electrically controlled, so that the discharge refrigerant pressure Pd of the refrigeration cycle in the heating mode, which will be described later, should become a target high pressure Po. The first electric expansion valve 12 includes an electrical actuator mechanism 12a and a valve mechanism.

The outside heat exchanger 13 is with an outlet side of the first electric expansion valve 12 connected. The refrigerant cycle system 10 according to the second embodiment has a first bypass passage 14a , The first detour passage 14a connects the outlet side of the utilization side heat exchanger 6 directly to an inlet side of the outside heat exchanger 13 so that the refrigerant is the first electrical expansion valve 12 can handle. A first opening / closing valve 14 is in the first bypass passage 14a arranged to the first bypass passage 14a to open and close. The first opening / closing valve 14 is an electromagnetic valve that is controlled to be opened and closed by the control voltage provided by the air conditioner controller 20 is issued.

In the cooling mode, which will be described later, the outside heat exchanger operates 13 as a heat radiating heat exchanger, which cools the refrigerant by radiating heat of the refrigerant to the outside air in a manner analogous to that in the first embodiment. In the heating mode, the outside heat exchanger operates 13 as a heat-absorbing heat exchanger, which evaporates the refrigerant by absorbing heat from the outside air.

A first refrigerant passage 15a of the indoor heat exchanger 15 is with an outlet side of the outside heat exchanger 13 connected. In the cooling mode, which will be described later, the indoor heat exchanger cools 15 the refrigerant on the outlet side of the outside heat exchanger 13 by exchanging heat between the refrigerant on the outlet side of the outside heat exchanger 13 , which is the first refrigerant pressure step 15a of the indoor heat exchanger 15 passes through, and the refrigerant on a suction side of the electric compressor 11 that a second refrigerant passage 15b of the indoor heat exchanger 15 passes.

The second electric expansion valve 16 acting as a variable throttle mechanism is on an outlet side of the first refrigerant passage 15a of the indoor heat exchanger 15 arranged. The second electric expansion valve 16 has essentially the same structure as the first electric expansion valve 12 and has an electrical actuator mechanism 16a and a valve mechanism.

In the cooling mode, which will be described later, the second electric expansion valve operates 16 also as a high pressure control valve. The opening degree of the high pressure control valve is controlled by the control signals provided by the air conditioning control 20 are output, electrically controlled, so that the discharge refrigerant pressure Pd is the target high pressure Po. The evaporator 5 is with an outlet side of the second electric expansion valve 16 connected.

In addition, the refrigeration cycle system has 10 according to the second embodiment, a second bypass passage 17a , The second detour passage 17a connects an inlet side of the first refrigerant passage 15a of the indoor heat exchanger 15 directly to an outlet side of the evaporator 5 so that the refrigerant is the second electrical expansion valve 16 can handle. There is also a second opening / closing valve 17 in the second bypass passage 17a arranged to the second bypass passage 17a to open and close.

The second opening / closing valve 17 has substantially the same structure as the first opening / closing valve 14 and is an electromagnetic valve that is controlled by the control voltage provided by the air conditioning control 20 is issued, opened and closed. The accumulator 18 is on a downstream side of the evaporator 5 and the second bypass passage 17a arranged. In addition, an inlet side of the second refrigerant passage 15b of the indoor heat exchanger 15 with an outlet of the accumulator 18 , from which gas-phase refrigerant flows, connected. The suction side of the electric compressor 11 is with an outlet side of the second refrigerant passage 15b connected.

The air conditioning control 20 performs various calculations and procedures based on a control program stored in the ROM to operate the aforementioned actuators 4a . 11b . 12a . 13a . 14 . 16a . 17 , etc. to control.

In addition, an input side of the air conditioning control 20 in addition to the structure of the first embodiment with a suction pressure sensor 35 , a suction refrigerant temperature sensor 36 , a discharge refrigerant temperature sensor 37 a use-side refrigerant temperature sensor 38 connected, etc. The suction pressure sensor 35 serves to detect the Ansaugkältemitteldrucks Ps of the electric compressor 11 , The intake refrigerant temperature sensor 36 serves to detect the Ansaugkältemitteltemperatur Ts of the electric compressor 11 , The discharge refrigerant temperature sensor 37 serves to detect the discharge refrigerant temperature Td of the electric compressor 11 , The use-side refrigerant temperature sensor 38 serves to detect the use-side refrigerant temperature Tco. Detection signals from these sensors 35 - 38 etc are in the input side of the air conditioning control 20 entered.

There is also an air conditioning control panel 40 provided with a Kühl- / Heizungsauswahlschalter etc. The cooling / heating selection switch is for selectively switching between the heating mode in which the air to be blown into the passenger compartment is heated, and the cooling mode in which the air to be blown into the passenger compartment is cooled.

Next, the operation of the refrigerant cycle system will be described hereinafter 10 according to the second embodiment having the structure described above. First, a basic operation of the refrigerant cycle system will be described hereinafter 10 when the cooling / heating selection switch of the air conditioner panel 40 is switched to the cooling mode described.

In the cooling mode, the first opening / closing valve becomes 14 opened, the first electric expansion valve 12 is completely closed, and the second opening / closing valve 17 will be closed. Consequently, in the cooling mode, the refrigerant flowing in the electric compressor radiates 11 has been compressed and has a high temperature and a high pressure, heat to the air in the utilization side heat exchanger (heater core) 6 from. The refrigerant coming from the utility side heat exchanger 6 has flowed out, flows through the first bypass passage 14a in the outside heat exchanger 13 and also radiates heat to the outside air and is cooled.

The refrigerant coming from the outside heat exchanger 13 has flowed out, flows into the first refrigerant passage 15a of the indoor heat exchanger 15 and exchanges heat with the suction refrigerant of the electric compressor 11 that in the electric compressor 11 is sucked in and the second refrigerant passage 15b passes through, and is cooled further, so that the enthalpy of the refrigerant is reduced. Consequently, the enthalpy difference (refrigeration capacity) between the refrigerant at the inlet of the evaporator becomes 5 and the refrigerant at the outlet of the evaporator 5 increased.

The pressure of the refrigerant from the first refrigerant passage 15a of the indoor heat exchanger 15 has passed, is at the second electric expansion valve 16 reduced. The refrigerant, its pressure on the second electric expansion valve 16 was lowered, flows into the evaporator 5 and absorbs heat from the air and evaporates. Therefore, the air that is blown into the passenger compartment is cooled. Consequently, the refrigerant flowing from the evaporator flows 5 has emanated, into the accumulator 18 and a gas-phase refrigerant is separated from the liquid-phase refrigerant. In addition, the gas-phase refrigerant that comes from the accumulator 18 has flowed through the second refrigerant passage 15b of the indoor heat exchanger 15 in the electric compressor 11 sucked.

In the heating mode, the first opening / closing valve becomes 14 closed, the second opening / closing valve 17 is opened, and the second electric expansion valve 16 is completely closed. Consequently, the refrigerant that is in the electric compressor radiates 11 has been compressed and has the high temperature and the high pressure, in the heating mode, heat to the air in the utilization side heat exchanger 6 from.

The pressure of the refrigerant coming from the use side heat exchanger 6 has flowed out, is at the first electric expansion valve 12 reduced. The refrigerant, its pressure at the first electric expansion valve 12 has decreased, takes on the outside heat exchanger 13 Heat from the outside air and is evaporated. The refrigerant coming from the outside heat exchanger 13 has flowed out, flows through the second bypass passage in turn 17a , the accumulator 18 and the second refrigerant passage 15b of the indoor heat exchanger 15 and gets into the electric compressor 11 sucked.

Next, hereinafter, the temperature protection control in the second embodiment in which the first and second electric expansion valves 12 . 16 work to the electric motor 11a of the electric compressor 11 protect with reference to 6 . 7A . 7B described. 6 FIG. 10 is a flowchart illustrating a method of setting the opening degrees of the first and second expansion valves. FIG 12 . 16 shows that from the air conditioning control 20 is performed in the second embodiment. 7A . 7B are control characteristic diagrams, the judgment scale values of the motor current of the electric motor 11a of the electric compressor 11 in the second embodiment, in conjunction with the speed of the electric motor 11a be determined. 7A shows the control line diagram in the cooling mode. 7B shows the control line diagram in the heating mode.

First, the air conditioner controller reads 20 at step S100, the detection signals of the sensors, the various air conditioning operation signals received from the air conditioning control panel 40 be sent, etc.

In particular, the air conditioner controller reads 20 the discharge refrigerant pressure Pd supplied from a discharge pressure sensor 31 is detected, the outside refrigerant temperature Tho, that of an outside refrigerant temperature sensor 32 is detected, the use-side refrigerant temperature Tco, that of a use-side refrigerant temperature sensor 38 is detected, the value of the motor current supplied by the power converter unit 19 to the electric motor 11a is output, the rotational speed of the electric motor 11a , etc. Also captures the air conditioning control 20 whether the cooling / heating selector switch of the air conditioner control panel 40 is switched to the cooling mode or the heating mode.

Next determines the air conditioning control 20 at step S110, whether the cooling / heating selection switch of the air conditioner panel 40 is switched to the cooling mode or not. When it is determined that the cooling / heating selection switch of the air conditioner panel 40 is switched to the cooling mode, calculates the air conditioning control 20 in step S210, a control amount of the opening degree of the second electric expansion valve 16 such that the discharge refrigerant pressure Pd of the electric compressor 11 the target high pressure Po may be based on the outside refrigerant temperature Tho of the outside heat exchanger 13 is determined.

In the second embodiment, the refrigerant exchanged with the outside heat exchanger 13 has flowed out, in the cooling mode on the inner heat exchanger 15 Heat with the suction refrigerant of the electric compressor 11 out. Therefore, the suction refrigerant of the electric compressor becomes 11 from the refrigerant coming from the outside heat exchanger 13 is out, heated, and the temperature of the Ansaugkältemittels is higher than that in the heating mode. Consequently, in the cooling mode, the discharge refrigerant temperature becomes higher than in the heating mode, so that the temperature of the electric motor 11a continues to rise than in the heating mode. That is, the temperature of the suction refrigerant of the electric compressor 11 differs in the cooling mode from that in the heating mode, and the temperature of the electric motor 11a differs in the cooling mode of the heating mode, even if the motor current and the speed of the electric motor 11a each are the same.

For this reason, in the second embodiment, the control characteristic for the cooling mode (see FIG 7A ) and the control characteristic for the heating mode (see 7B ) separated in advance in the ROM etc. of the air conditioning control 20 saved. As in 7A . 7B 2, the judgment scale temperature in the control characteristic for the cooling mode is lower than the judgment scale temperature in the control characteristic for the heating mode. Two or more control characteristics in which the judgment scale values are different become, for each mode, in the ROM etc. of the air conditioner controller 20 saved.

Next, select the air conditioning control 20 in step S310, the control characteristic for the cooling mode. Then calculate and record the Air conditioning control 20 based on the selected control characteristic, the temperature of the electric motor 11a from the detected speed and the motor current of the electric motor 11a , In addition, the air conditioning control calculates 20 in which area of the control characteristic for the cooling mode, the detected temperature of the electric motor 11a is, and the process goes to step S400.

If it is determined in step S110 that the cooling / heating selection switch of the air conditioner panel 40 is switched to the heating mode, calculates the air conditioner control 20 at step S220, a control amount of the opening degree of the first electric expansion valve 12 such that the discharge refrigerant pressure Pd of the electric compressor 11 the target high pressure Po may be based on the outside refrigerant temperature Tho of the outside heat exchanger 13 is determined.

Next, select the air conditioning control 20 in step S310, the control characteristic for the cooling mode. Then calculates and records the air conditioning control 20 based on the selected control characteristic, the temperature of the electric motor 11a from the detected speed and the motor current of the electric motor 11a , In addition, the air conditioner controller calculates 20 in which area of the control characteristic for the heating mode, the detected temperature of the electric motor 11a is, and the process goes to step S400. The processes at steps S310, S320 correspond to a control characteristic selection means.

As explained above, in each mode, a control characteristic adapted for the mode is selected from two or more control characteristics in which the judgment scale values are different, and the temperature of the electric motor 11a is detected based on the selected control characteristic. By determining whether the detected temperature of the electric motor 11a is higher than (or equal to) the judgment scale value of the selected control characteristic or not, it is possible to determine in the temperature protection control for the electric motor 11a perform. This will increase the reliability of the temperature protection control of the electric motor 11a elevated.

Third Embodiment

When Next, a third embodiment will be described hereinafter of the present invention. Elements that are essentially the same or equivalent to those in the first and second Embodiments are have the same reference numbers as in the first and second embodiments and not described again.

In the second embodiment described above, a certain control characteristic corresponding to the operation mode and the temperature of the electric motor 11a from the detection value of the converter unit 19 calculated and recorded on the basis of the selected control characteristic. In contrast, in the third embodiment, two or more control characteristics in which the judgment scale values are different are in advance in the ROM etc. of the air conditioner controller 20 saved. Then, a certain control characteristic corresponding to a degree of superheat of the refrigerant on the suction side of the electric compressor 11 selected from the two or more control characteristics, and the temperature of the electric motor 11a is from the detection value of the power converter unit 19 calculated.

Specifically, the suction refrigerant pressure Ps of the electric compressor becomes 11 from the suction pressure sensor 35 detected, and the Ansaugkältemitteltemperatur Ts of the electric compressor 11 is from the intake refrigerant temperature sensor 36 detected. Then, the saturated steam temperature of the refrigerant is calculated from the detected suction refrigerant pressure Ps, and the superheat degree SH of the refrigerant on the suction side of the electric compressor 11 is calculated from the intake refrigerant temperature Ts and the saturated steam temperature. Alternatively, the Ansaugkältemitteldruck Ps from the blown air temperature Te of the evaporator 5 be evaluated by a reboiler air temperature sensor 33 is detected.

When the superheat degree SH of the refrigerant on the suction side of the electric compressor 11 is high, the temperature of the electric motor increases 11a , Therefore, a control characteristic in which the judgment scale value is set low is selected from two or more control characteristics. When the superheat degree SH of the refrigerant on the suction side of the electric compressor 11 is small, the temperature of the electric motor increases 11a not so strong. Therefore, a control characteristic in which the judgment scale value is set high is selected from two or more control characteristics.

As explained above, based on the superheat degree SH of the refrigerant on the suction side of the electric compressor 11 a certain control characteristic is selected from predetermined two or more control characteristics in which the judgment scale values are different, and the temperature of the electric motor 11a is calculated and recorded based on the certain control characteristic. Consequently, it is possible to determine in the temperature protection control for the electric motor 11a perform. This will increase the reliability of the temperature protection control of the electric motor 11a elevated.

Here is the control method in the third embodiment not only to that described in the second embodiment Heat pump cycle system, but also on the in the First embodiment described refrigerant cycle system applicable.

Other Embodiments

• (1) In den vorstehend beschriebenen Ausführungsformen wird die Temperatur des Elektromotors 11a des elektrischen Kompressors 11 unter Verwendung der Steuerkennlinie, die die Temperatur des Elektromotors 11a mit der Drehzahl und dem Motorstrom des Elektromotors 11a verknüpft, berechnet und erfasst. Die vorliegende Erfindung ist nicht auf diesen Aufbau beschränkt. Zum Beispiel kann die Temperatur des Elektromotors 11a durch einen Temperatursensor zum Erfassen der Innentemperatur des Elektromotors 11a, einen Temperatursensor zum Erfassen der Temperatur eines Gehäuses des Elektromotors 11a etc. erfasst werden.
• (2) In den vorstehend beschriebenen Ausführungsformen werden die Öffnungsgrade der elektrischen Expansionsventile 12, 16 direkt in der Temperaturschutzsteuerung für den Elektromotor 11a des elektrischen Kompressors 11 eingestellt. Die vorliegende Erfindung ist nicht auf diesen Aufbau beschränkt. Zum Beispiel kann der Ausstoßkältemitteldruck Pd des elektrischen Kompressors 11 gesenkt werden, indem der Zielhochdruck gesenkt wird, der basierend auf der Temperatur (außenseitige Kältemitteltemperatur) Tho des Kältemittels auf der Auslassseite des Außenseiten-Wärmetauschers 13 oder des nutzungsseitigen Wärmetauschers 6, der als der wärmeabstrahlende Wärmetauscher wirkt, bestimmt wird.
• (3) In den vorstehend beschriebenen Ausführungsformen wird die Temperaturschutzsteuerung für den Elektromotor 11a des elektrischen Kompressors 11 durchgeführt, indem der Öffnungsgrad des elektrischen Expansionsventils 16 gesteuert wird, so dass er nicht abnimmt, wenn der Temperaturschutz für den Elektromotor 11a des elektrischen Kompressors 11 notwendig ist. Alternativ ist es auch möglich, neben der Steuerung des Öffnungsgrads des elektrischen Expansionsventils 16 die Drehzahl des Elektromotors 13b des Kühlventilators (erstes elektrisches Gebläse) 13a zu erhöhen.

The present embodiment is not limited to the above-described embodiments and can be modified in many ways as follows.

• (1) In the above-described embodiments, the temperature of the electric motor becomes 11a of the electric compressor 11 using the control characteristic, which is the temperature of the electric motor 11a with the speed and the motor current of the electric motor 11a linked, calculated and recorded. The present invention is not limited to this structure. For example, the temperature of the electric motor 11a by a temperature sensor for detecting the internal temperature of the electric motor 11a a temperature sensor for detecting the temperature of a housing of the electric motor 11a etc. are recorded.
• (2) In the embodiments described above, the opening degrees of the electric expansion valves 12 . 16 directly in the temperature protection control for the electric motor 11a of the electric compressor 11 set. The present invention is not limited to this structure. For example, the discharge refrigerant pressure Pd of the electric compressor 11 can be lowered by lowering the target high pressure based on the temperature (outside refrigerant temperature) Tho of the refrigerant on the outlet side of the outside heat exchanger 13 or the utilization-side heat exchanger 6 which acts as the heat-radiating heat exchanger is determined.
• (3) In the above-described embodiments, the temperature protection control for the electric motor becomes 11a of the electric compressor 11 performed by the opening degree of the electric expansion valve 16 is controlled so that it does not decrease when the temperature protection for the electric motor 11a of the electric compressor 11 necessary is. Alternatively, it is also possible besides controlling the opening degree of the electric expansion valve 16 the speed of the electric motor 13b the cooling fan (first electric fan) 13a to increase.

• (4) Außerdem ist es auch möglich, die Drehzahl des Elektromotors 4a des elektrischen Gebläses (zweites elektrisches Gebläse) 4 zu senken, wenn der Temperaturschutz für den Elektromotor 11a des elektrischen Kompressors 11 notwendig ist.

By increasing the speed of the cooling fan 13a The temperature of the refrigerant on the outlet side of the heat-radiating heat exchanger 6 . 13 lowered and the target high pressure is lowered. Thereby, the pressure (discharge refrigerant pressure Pd) of the refrigerant on the discharge side of the electric compressor becomes 11 lowered, and the temperature rise of the electric motor 11a is avoided.

• (4) In addition, it is also possible, the rotational speed of the electric motor 4a electric fan (second electric fan) 4 lower when the temperature protection for the electric motor 11a of the electric compressor 11 necessary is.

• (5) Ferner kann die Innen-/Außenluftumschaltklappe 3c auf die Innenluftbetriebsart umgeschaltet werden, wenn der Temperaturschutz für den Elektromotor 11a des elektrischen Kompressors 11 notwendig ist. Durch Umschalten der Innen-/Außenluftumschaltklappe 3c auf die Innenluftbetriebsart wird die Kühlkapazität des Verdampfers 5 gesenkt, und der Überhitzungsgrad des Kältemittels auf der Ansaugseite des elektrischen Kompressors 11 wird gesenkt. Dadurch wird der Druck (Ansaugkältemitteldruck Ps) des Kältemittels auf der Ansaugseite des elektrischen Kompressors 11 gesenkt, und der Temperaturanstieg des Elektromotors 11a wird vermieden.
• (6) In der vorstehend beschriebenen zweiten Ausführungsform werden verschiedene Steuerkennlinien, in denen die Beurteilungsmaßstabswerte unterschiedlich sind, für die Kühlbetriebsart und die Heizbetriebsart ausgewählt. Die vorliegende Erfindung ist nicht auf diesen Aufbau beschränkt. Zum Beispiel kann die Steuerkennlinie für die Heizbetriebsart in einer Entfeuchtungsbetriebsart angewendet werden. Eine Steuerkennlinie für die Entfeuchtungsbetriebsart kann in der Entfeuchtungsbetriebsart ausgewählt werden.
• (7) Außerdem ist der Überhitzungsgrad des Kältemittels auf der Ansaugseite des elektrischen Kompressors 11 in der vorstehend beschriebenen zweiten Ausführungsform selbst in der Kühlbetriebsart klein, wenn der elektrische Kompressor 11 gerade angeschaltet wurde. Daher kann die gleiche Steuerkennlinie wie die für die Heizbetriebsart ausgewählt werden, wenn der Überhitzungsgrad des Kältemittels kleiner als ein vorgegebener Wert ist, und die gleiche Steuerkennlinie wie die für die Kühlbetriebsart kann ausgewählt werden, wenn der Überhitzungsgrad des Kältemittels höher als ein vorgegebener Wert ist.
• (8) Außerdem kann das vorstehend beschriebene Kältemittelkreislaufsystem 10 auf ein Ejektorkreislaufsystem angewendet werden, das durch Dokumente, wie etwa JP 3322263 B1 , das den US-Patenten Nr. 6 477 857 und 6 574 987 entspricht, öffentlich bekannt ist. In diesem Fall wird der variable Drosselmechanismus durch einen Ejektor, der mit einer variablen Nadel versehen ist, ersetzt.
• (9) In den vorstehend beschriebenen Ausführungsformen wird das Kältemittelkreislaufsystem 10 gemäß der vorliegenden Erfindung auf ein Fahrzeugklimatisierungssystem angewendet. Die vorliegende Erfindung ist nicht auf diese Beispiele beschränkt. Zum Beispiel kann das Kältemittelkreislaufsystem gemäß der vorliegenden Erfindung auf ein festes Klimatisierungssystem für die Privatanwendung oder die gewerbliche Anwendung angewendet werden. Außerdem kann das Kältemittelkreislaufsystem nicht nur auf ein Klimatisierungssystem angewendet werden, das zwischen der Kühlbetriebsart und der Heizbetriebsart umgeschaltet werden kann, sondern auch auf ein dediziertes Kühlsystem.
• (10) Außerdem ist in dem vorstehend beschriebenen Kältemittelkreislaufsystem 10 die Art des Kältemittels nicht spezifiziert. Das Kältemittel kann Fluorchlorkohlenwasserstoff, ein Ersatzstoff für Fluorchlorkohlenwasserstoff, wie etwa HC-Kältemittel, Kohlendioxid (CO₂), die sowohl auf ein überkritisches Dampfkompressionskältemittelkreislaufsystem als auch ein unterkritisches Dampfkompressionskältemittelkreislaufsystem angewendet werden können, etc. sein.

By lowering the speed of the electric fan 4 is the cooling capacity of the evaporator 5 increases, and the degree of superheat of the refrigerant on the suction side of the electric compressor 11 is lowered. Thereby, the pressure (suction refrigerant pressure Ps) of the refrigerant on the suction side of the electric compressor becomes 11 lowered, and the temperature rise of the electric motor 11a is avoided.

• (5) Further, the inside / outside air switching door can 3c Switched to the indoor air mode when the temperature protection for the electric motor 11a of the electric compressor 11 necessary is. By switching the inside / outside air switching door 3c on the indoor air mode is the cooling capacity of the evaporator 5 lowered, and the degree of superheat of the refrigerant on the suction side of the electric compressor 11 is lowered. Thereby, the pressure (suction refrigerant pressure Ps) of the refrigerant on the suction side of the electric compressor becomes 11 lowered, and the temperature rise of the electric motor 11a is avoided.
• (6) In the second embodiment described above, various control characteristics in which the judgment scale values are different are selected for the cooling mode and the heating mode. The present invention is not limited to this structure. For example, the heating mode control characteristic may be applied in a dehumidifying mode. A control characteristic for the dehumidifying mode can be selected in the dehumidifying mode.
• (7) In addition, the degree of superheat of the refrigerant is on the suction side of the electric compressor 11 in the above-described second embodiment, even in the cooling mode, small when the electric compressor 11 just turned on. Therefore, the same control characteristic as that for the heating mode can be selected when the superheat degree of the refrigerant is less than a predetermined value, and the same control characteristic as that for the cooling mode can be selected when the superheat degree of the refrigerant is higher than a predetermined value.
• (8) In addition, the above-described refrigerant cycle system 10 be applied to an ejector cycle system, which by documents, such as JP 3322263 B1 that the U.S. Pat. Nos. 6,477,857 and 6 574 987 corresponds, is publicly known. In this case, the variable throttle mechanism is replaced by an ejector provided with a variable needle.
• (9) In the above-described embodiments, the refrigerant cycle system 10 according to the present invention applied to a vehicle air conditioning system. The present invention is not limited to these examples. For example, the refrigerant cycle system according to the present invention may be applied to a fixed air conditioning system for home or commercial use. In addition, the refrigerant cycle system can be applied not only to an air conditioning system that can be switched between the cooling mode and the heating mode, but also to a dedicated cooling system.
• (10) In addition, in the refrigerant cycle system described above 10 the type of refrigerant is not specified. The refrigerant may be chlorofluorocarbon, a substitute for chlorofluorohydrocarbon such as HC refrigerant, carbon dioxide (CO ₂ ), which may be applied to both a supercritical vapor compression refrigeration cycle system and a subcritical vapor compression refrigeration cycle system, etc.

additional Advantages and modifications will be readily apparent to those skilled in the art come to mind. The invention is therefore not in its broader sense the specific details, the representative device and illustrative examples shown and described are limited.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - JP 2006-291878 A [0002, 0003, 0004, 0005]
• - JP 2005-248730 A [0002, 0003, 0005]
• - JP 2006-291878 [0005]
• - JP 3322263 B1 [0118]
• US 6477857 [0118]
• US 6574987 [0118]

Claims (11)

Refrigerant cycle system, comprising: an electric compressor ( 11 ), which has a compression mechanism ( 11b ), which draws and compresses refrigerant, and an electric motor ( 11a ), the compression mechanism ( 11b ) and by the refrigerant on a suction side of the compression mechanism ( 11b ) is cooled; a variable throttle mechanism ( 12 . 16 ), that of the electric compressor ( 11 ) discharged refrigerant decompressed; an engine temperature detection device ( 20 ), which is a temperature of the electric motor ( 11a ) detected; a motor protection determining device ( 20 ), which determines whether the temperature of the electric motor ( 11a ) detected by the engine temperature detector ( 20 ) is equal to or higher than an assessment scale value; and a motor protection control ( 20 ), the variable throttle mechanism ( 12 . 16 ) so that the degree of opening of the variable throttle mechanism ( 12 . 16 ) does not decrease when the engine protection determining device determines that the temperature of the electric motor ( 11a ) is equal to or higher than a judgment scale value. Refrigerant cycle system according to claim 1, further comprising a drive circuit ( 19 ), which controls the operation of the electric motor ( 11a ), wherein: the drive circuit ( 19 ) a motor current which is connected to the electric motor ( 11a ) output electric current, and a rotational speed of the electric motor ( 11a ) detected; and the engine temperature detection device ( 20 ) the temperature of the electric motor ( 11a ) detected by the temperature of the electric motor ( 11a ) from the speed and the motor current of the electric motor ( 11a ) generated by the drive circuit ( 19 ) are calculated with reference to a control map data field which is prepared in advance and which has a relationship of the temperature of the electric motor ( 11a ) with respect to the rotational speed and the motor current of the electric motor ( 11a ) indicates. The refrigerant cycle system according to claim 2, wherein: the judgment scale value in the control map data field is specified to match the rotational speed and the motor current of the electric motor ( 11a ) correspond to; and the engine protection determination device ( 20 ) determines whether the temperature of the electric motor ( 11a ) detected by the engine temperature detector ( 20 ) is equal to or higher than the judgment scale value specified in the control line data field. The refrigerant cycle system according to claim 3, wherein: the judgment scale value specified in the control-line data field is a first judgment-scale value; a second judgment scale value higher than the first judgment criterion value specified in the control map data field; the motor protection determining device ( 20 ) determines whether the temperature of the electric motor ( 11a ) detected by the engine temperature detector ( 20 ) is equal to or higher than the first rating scale value; the motor protection determining device ( 20 ) determines whether the temperature of the electric motor ( 11a ) detected by the engine temperature detector ( 20 ) is equal to or higher than the second judgment scale value when the engine protection determination device ( 20 ) determines that the temperature of the electric motor ( 11a ) detected by the engine temperature detector ( 20 ) is equal to or higher than the first rating scale value; the motor protection control the variable throttle mechanism ( 12 . 16 ) so that the degree of opening of the variable throttle mechanism ( 12 . 16 ) does not decrease when the engine protection determining device determines that the temperature of the electric motor ( 11a ) detected by the engine temperature detector ( 20 ) is equal to or higher than the first judgment scale value and is lower than the second judgment benchmark value; and the motor protection control the variable throttle mechanism ( 12 . 16 ) so that the degree of opening of the variable throttle mechanism ( 12 . 16 ) increases when the engine protection determination device determines that the temperature of the electric motor ( 11a ) calculated by the engine temperature detecting means is equal to or higher than the second judgment scale value. The refrigerant cycle system according to claim 3 or 4, further comprising: suction refrigerant superheat degree detecting means (16); 20 . 35 . 36 ), which is a degree of superheat of the refrigerant on the suction side of the electric compressor ( 11 ) detected; and a control characteristic selector ( 20 ), which is a control line data field of a plurality of control line data fields, each of which is prepared in advance and a relationship of the temperature of the electric motor ( 11a ) with respect to the rotational speed and the motor current of the electric motor ( 11a ), based on the superheat degree of the refrigerant discharged from the suction refrigerant superheat degree detecting means (FIG. 20 . 35 . 36 ), wherein the engine protection determination device determines whether the temperature of the electric motor ( 11a ) detected by the engine temperature detector ( 20 ) be is equal to or higher than the judgment scale value specified in the one control map data field. The refrigerant cycle system according to claim 3, wherein the refrigerant cycle system is a heat pump system that operates in a cooling mode in which the refrigerant cools heat exchange target fluid and in a heating mode in which the refrigerant heats heat exchange target fluid, wherein the refrigerant cycle system further comprises: a control characteristic selection device ( 20 ) which, in a cooling mode, generates a first control map data field from a plurality of control map data fields each of which is prepared in advance and a relationship of the temperature of the electric motor ( 11a ) with respect to the rotational speed and the motor current of the electric motor ( 11a ), and in the heating mode selects a second control map data field from the plurality of control map data fields so that the judgment scale value specified in the first control map data field is lower than the judgment benchmark value specified in the second control map data field, the engine protection determination means determines whether the temperature of the electric motor ( 11a ) detected by the engine temperature detector ( 20 ) is equal to or higher than the judgment scale value specified in the first control-line data field or the second control-line data field, which is output from the control-characteristic-selecting means (FIG. 20 ) is selected. A refrigerant cycle system according to any one of claims 1 to 6, further comprising a heat radiating heat exchanger (10). 6 . 13 ), the refrigerant on an ejection side of the electric compressor ( 11 ), wherein: the variable throttle mechanism ( 12 . 16 ) the refrigerant on an outlet side of the heat-radiating heat exchanger ( 6 . 13 decompressed so that a pressure of the refrigerant on the discharge side of the electric compressor ( 11 ) comes closer to a target high pressure, which is based on a temperature of the refrigerant on the outlet side of the heat radiating heat exchanger ( 6 . 13 ) is determined; and the engine protection control lowers the target high pressure when the temperature of the electric motor ( 11a ) detected by the engine temperature detecting means is equal to or higher than the judgment scale value. The refrigerant cycle system according to claim 7, further comprising: a first electric blower (FIG. 13a ), the outside air to the heat radiating heat exchanger ( 13 ) blows; and a first electric fan control ( 20 ), which is a speed of the first electric blower ( 13a ), wherein the first electric blower control controls the speed of the first electric blower ( 13a ), when the engine protection determining device ( 20 ) determines that the temperature of the electric motor ( 11a ) detected by the engine temperature detector ( 20 ) is equal to or higher than the judgment scale value. A refrigerant cycle system according to any of claims 6 to 8, further comprising: an evaporator ( 5 ), that of the variable throttle mechanism ( 12 . 16 decompressed refrigerant vaporizes; a second electric blower ( 4 ), the heat exchange target fluid to the evaporator ( 5 ) blows; and a second electric fan control ( 20 ), which is a speed of the second electric blower ( 4 ), wherein the second electric blower control ( 20 ) the speed of the second electric fan ( 4 ), when the engine protection determining device ( 20 ) determines that the temperature of the electric motor ( 11a ) detected by the engine temperature detecting means is equal to or higher than the judgment scale value. A refrigerant cycle system according to any of claims 6 to 8, further comprising: an evaporator ( 5 ), which contains the refrigerant which is supplied by the variable throttle mechanism ( 12 . 16 ) is decompressed, evaporated; and an indoor / outdoor air switch ( 20 ) having an air induction mechanism ( 3 ) between an indoor air mode in which to the evaporator ( 5 blown air is introduced from an interior, and an outside air mode in which the to the evaporator ( 5 blown air from outside is switched, the inside / outside air switch ( 20 ) the air induction mechanism ( 3 ) switches to the inside air mode when the engine protection determination device ( 20 ) determines that the temperature of the electric motor ( 11a ) detected by the engine temperature detector ( 20 ) is equal to or higher than the judgment scale value. The refrigerant cycle system according to claim 1, wherein the engine temperature detection means comprises an engine temperature detection sensor for detecting the temperature of the electric motor. 11a ).